The importance of clinical surveillance in detecting legionnaires' disease outbreaks: a large outbreak in a hospital with a Legionella disinfection system-Pennsylvania, 2011-2012.

BACKGROUND: Healthcare-associated Legionnaires' disease (LD) is a preventable pneumonia with a 30% case fatality rate. The Centers for Disease Control and Prevention guidelines recommend a high index of suspicion for the diagnosis of healthcare-associated LD. We characterized an outbreak and evaluated contributing factors in a hospital using copper-silver ionization for prevention of Legionella growth in water. METHODS: Through medical records review at a large, urban tertiary care hospital in November 2012, we identified patients diagnosed with LD during 2011-2012. Laboratory-confirmed cases were categorized as definite, probable, and not healthcare associated based on time spent in the hospital during the incubation period. We performed an environmental assessment of the hospital, including collection of samples for Legionella culture. Clinical and environmental isolates were compared by genotyping. Copper and silver ion concentrations were measured in 11 water samples. RESULTS: We identified 5 definite and 17 probable healthcare-associated LD cases; 6 case patients died. Of 25 locations (mostly potable water) where environmental samples were obtained for Legionella-specific culture, all but 2 showed Legionella growth; 11 isolates were identical to 3 clinical isolates by sequence-based typing. Mean copper and silver concentrations were at or above the manufacturer's recommended target for Legionella control. Despite this, all samples where copper and silver concentrations were tested showed Legionella growth. CONCLUSIONS: This outbreak was linked to the hospital's potable water system and highlights the importance of maintaining a high index of suspicion for healthcare-associated LD, even in the setting of a long-term disinfection program.

Veterans Affairs initiative to prevent methicillin-resistant Staphylococcus aureus infections.

BACKGROUND: Health care-associated infections with methicillin-resistant Staphylococcus aureus (MRSA) have been an increasing concern in Veterans Affairs (VA) hospitals. METHODS: A "MRSA bundle" was implemented in 2007 in acute care VA hospitals nationwide in an effort to decrease health care-associated infections with MRSA. The bundle consisted of universal nasal surveillance for MRSA, contact precautions for patients colonized or infected with MRSA, hand hygiene, and a change in the institutional culture whereby infection control would become the responsibility of everyone who had contact with patients. Each month, personnel at each facility entered into a central database aggregate data on adherence to surveillance practice, the prevalence of MRSA colonization or infection, and health care-associated transmissions of and infections with MRSA. We assessed the effect of the MRSA bundle on health care-associated MRSA infections. RESULTS: From October 2007, when the bundle was fully implemented, through June 2010, there were 1,934,598 admissions to or transfers or discharges from intensive care units (ICUs) and non-ICUs (ICUs, 365,139; non-ICUs, 1,569,459) and 8,318,675 patient-days (ICUs, 1,312,840; and non-ICUs, 7,005,835). During this period, the percentage of patients who were screened at admission increased from 82% to 96%, and the percentage who were screened at transfer or discharge increased from 72% to 93%. The mean (±SD) prevalence of MRSA colonization or infection at the time of hospital admission was 13.6±3.7%. The rates of health care-associated MRSA infections in ICUs had not changed in the 2 years before October 2007 (P=0.50 for trend) but declined with implementation of the bundle, from 1.64 infections per 1000 patient-days in October 2007 to 0.62 per 1000 patient-days in June 2010, a decrease of 62% (P<0.001 for trend). During this same period, the rates of health care-associated MRSA infections in non-ICUs fell from 0.47 per 1000 patient-days to 0.26 per 1000 patient-days, a decrease of 45% (P<0.001 for trend). CONCLUSIONS: A program of universal surveillance, contact precautions, hand hygiene, and institutional culture change was associated with a decrease in health care-associated transmissions of and infections with MRSA in a large health care system.

Identifying the incidence of and risk factors for reamputation among patients who underwent foot amputation.

BACKGROUND: Many patients who have lower-extremity amputations secondary to peripheral vascular disease or diabetes require reamputation eventually. This study was designed to identify the incidence of and risk factors for ipsilateral reamputation after forefoot amputation, to evaluate whether postoperative infection increases the risk of reamputation, and to evaluate whether the risk of reamputation was reduced by the duration of antimicrobial therapy after amputation. METHODS: A retrospective analysis of patients who underwent foot amputation for nontraumatic reason from January 2002 to December 2004 at the Veterans Affairs Pittsburgh Healthcare System was performed. RESULTS: Among 116 patients, 57 (49.1%) had ipsilateral reamputation within 3 years after their first surgeries; 78.9% received reamputation in the first 6 months; 53 (45.7%) died within 3 years; and 16 (13.8%) developed postoperative infections. Upper level of amputation, long duration of hospitalization, insulin-dependent diabetes, and gangrene on physical examination on admission were risk factors for reamputation in univariate analysis. Gangrene (odds ratio: 3.81, 95% confidence interval: 1.60-9.12, P = 0.003) and insulin-dependent diabetes (odds ratio: 2.93, 95% confidence interval: 1.26-6.78, P = 0.012) were risk factors in multivariate analysis. Postoperative infection did not increase the risk of reamputation. Longer than 2-week course of antibiotic use after amputation did not prevent reamputation. CONCLUSIONS: Approximately one-half of patients required ipsilateral reamputation and died in 3 years. Gangrene on admission and history of insulin-dependent diabetes were significant risk factors (P = 0.003, P = 0.028). Long duration of antibiotic use after amputation and postoperative infection did not change the risk of reamputation.

Protothecosis after liver transplantation.

Prototheca species are unicellular algae of low virulence that are rarely associated with human infections. We report a liver transplant recipient with disseminated protothecosis and review the literature on this unusual opportunistic infection in transplant recipients. Of 9 cases, including ours, 5 had a localized infection, and 4 had disseminated protothecosis. Seven cases were due to Prototheca wickerhamii, and 2 were due to Prototheca zopfii. Overall mortality in transplant recipients with Prototheca infections was 88% (7/8). All 4 cases of disseminated protothecosis died despite therapy with amphotericin B. Posttransplant protothecosis is a rare but significant infection that is associated with a grave prognosis.

Water Cultures Are More Sensitive Than Swab Cultures for the Detection of Environmental Legionella.

Water cultures were significantly more sensitive than concurrently collected swab cultures (n=2,147 each) in detecting Legionella pneumophila within a Veterans Affairs healthcare system. Sensitivity for water versus swab cultures was 90% versus 30% overall, 83% versus 48% during a nosocomial Legionnaires' disease outbreak, and 93% versus 22% post outbreak. Infect Control Hosp Epidemiol 2018;39:108-110.

Hand hygiene practices after brief encounters with patients: an important opportunity for prevention.

OBJECTIVE: To identify characteristics of encounters between healthcare workers (HCWs) and patients that correlated with hand hygiene adherence among HCWs. DESIGN: Observational study. SETTING: Intensive care unit in a Veterans Affairs hospital. PARTICIPANTS: HCWs. RESULTS: There were 767 patient encounters observed (48.6% involved nurses, 20.6% involved physicians, and 30.8% involved other HCWs); 39.8% of encounters involved patients placed under contact precautions. HCW contact with either the patient or surfaces in the patient's environment occurred during all encounters; direct patient contact occurred during 439 encounters (57.4%), and contact with environmental surfaces occurred during 710 encounters (92.6%). The median duration of encounters was 2 minutes (range, <1 to 51 minutes); 33.6% of encounters lasted 1 minute or less, with no significant occupation-associated differences in the median duration of encounters. Adherence with hand hygiene practices was correlated with the duration of the encounter, with overall adherences of 30.0% after encounters of < or =1 minute, 43.4% after encounters of >1 to < or =2 minutes, 51.1% after encounters of >3 to < or =5 minutes, and 64.9% after encounters of >5 minutes (P<.001 by the chi (2) for trend). In multivariate analyses, longer encounter duration, contact precautions status, patient contact, and nursing occupation were independently associated with adherence to hand hygiene recommendations. CONCLUSIONS: In this study, adherence to hand hygiene practices was lowest after brief patient encounters (i.e., < 2 minutes). Brief encounters accounted for a substantial proportion of all observed encounters, and opportunities for hand contamination occurred during all brief encounters. Therefore, improving adherence after brief encounters may have an important overall impact on the transmission of healthcare-associated pathogens and may deserve special emphasis in the design of programs to promote adherence to hand hygiene practices.

Role of environmental surveillance in determining the risk of hospital-acquired legionellosis: a national surveillance study with clinical correlations.

OBJECTIVE: Hospital-acquired Legionella pneumonia has a fatality rate of 28%, and the source is the water distribution system. Two prevention strategies have been advocated. One approach to prevention is clinical surveillance for disease without routine environmental monitoring. Another approach recommends environmental monitoring even in the absence of known cases of Legionella pneumonia. We determined the Legionella colonization status of water systems in hospitals to establish whether the results of environmental surveillance correlated with discovery of disease. None of these hospitals had previously experienced endemic hospital-acquired Legionella pneumonia. DESIGN: Cohort study. SETTING: Twenty US hospitals in 13 states. INTERVENTIONS: Hospitals performed clinical and environmental surveillance for Legionella from 2000 through 2002. All specimens were shipped to the Special Pathogens Laboratory at the Veterans Affairs Pittsburgh Medical Center. RESULTS: Legionella pneumophila and Legionella anisa were isolated from 14 (70%) of 20 hospital water systems. Of 676 environmental samples, 198 (29%) were positive for Legionella species. High-level colonization of the water system (30% or more of the distal outlets were positive for L. pneumophila) was demonstrated for 6 (43%) of the 14 hospitals with positive findings. L. pneumophila serogroup 1 was detected in 5 of these 6 hospitals, whereas 1 hospital was colonized with L. pneumophila serogroup 5. A total of 633 patients were evaluated for Legionella pneumonia from 12 (60%) of the 20 hospitals: 377 by urinary antigen testing and 577 by sputum culture. Hospital-acquired Legionella pneumonia was identified in 4 hospitals, all of which were hospitals with L. pneumophila serogroup 1 found in 30% or more of the distal outlets. No cases of disease due to other serogroups or species (L. anisa) were identified. CONCLUSION: Environmental monitoring followed by clinical surveillance was successful in uncovering previously unrecognized cases of hospital-acquired Legionella pneumonia.

Isolation of Staphylococcus aureus from the urinary tract: association of isolation with symptomatic urinary tract infection and subsequent staphylococcal bacteremia.

BACKGROUND: Staphylococcus aureus is frequently isolated from urine samples obtained from long-term care patients. The significance of staphylococcal bacteriuria is uncertain. We hypothesized that S. aureus is a urinary pathogen and that colonized urine could be a source of future staphylococcal infection. METHODS: We performed a cohort study of 102 patients at a long-term care Veterans Affairs facility for whom S. aureus had been isolated from clinical urine culture. Patients were observed via urine and nasal cultures that were performed every 2 months. We determined the occurrence of (1) symptomatic urinary tract infection concurrent with isolation of S. aureus (by predetermined criteria), (2) staphylococcal bacteremia concomitant with isolation of S. aureus from urine, and (3) subsequent episodes of staphylococcal infection. RESULTS: Of 102 patients, 82% had undergone recent urinary catheterization. Thirty-three percent of patients had symptomatic urinary tract infection at the time of initial isolation of S. aureus, and 13% were bacteremic. Eight-six percent of the initial urine isolates were methicillin-resistant S. aureus. Seventy-one patients had follow-up culture data; 58% of cultures were positive for S. aureus at > or =2 months (median duration of staphylococcal bacteriuria, 4.3 months). Sixteen patients had subsequent staphylococcal infections, occurring up to 12 months after initial isolation of S. aureus; 8 late-onset infections were bacteremic. In 5 of 8 patients, the late blood isolate was found to have matched the initial urine isolate by pulsed-field gel electrophoresis typing. CONCLUSIONS: S. aureus is a cause of urinary tract infection among patients with urinary tract catheterization. The majority of isolates are methicillin-resistant S. aureus. S. aureus bacteriuria can lead to subsequent invasive infection. The efficacy of antistaphylococcal therapy in preventing late-onset staphylococcal infection in patients with persistent staphylococcal bacteriuria should be tested in controlled trials.

Improving the Diagnosis of Legionella Pneumonia within a Healthcare System through a Systematic Consultation and Testing Program.

RATIONALE: Legionella testing is not recommended for all patients with pneumonia, but rather for particular patient subgroups. As a result, the overall incidence of Legionella pneumonia may be underestimated. OBJECTIVES: To determine the incidence of Legionella pneumonia in a veteran population in an endemic area after introduction of a systematic infectious diseases consultation and testing program. METHODS: In response to a 2011-2012 outbreak, the VA Pittsburgh Healthcare System mandated infectious diseases consultations and testing for Legionella by urine antigen and sputum culture in all patients with pneumonia. MEASUREMENTS AND MAIN RESULTS: Between January 2013 and December 2015, 1,579 cases of pneumonia were identified. The incidence of pneumonia was 788/100,000 veterans per year, including 352/100,000 veterans per year and 436/100,000 veterans per year with community-associated pneumonia (CAP) and health care-associated pneumonia, respectively. Ninety-eight percent of patients with suspected pneumonia were tested for Legionella by at least one method. Legionella accounted for 1% of pneumonia cases (n = 16), including 1.7% (12/706) and 0.6% (4/873) of CAP and health care-associated pneumonia, respectively. The yearly incidences of Legionella pneumonia and Legionella CAP were 7.99 and 5.99/100,000 veterans, respectively. The sensitivities of urine antigen and sputum culture were 81% and 60%, respectively; the specificity of urine antigen was >99.97%. Urine antigen testing and Legionella cultures increased by 65% and 330%, respectively, after introduction of our program. CONCLUSIONS: Systematic testing of veterans in an endemic area revealed a higher incidence of Legionella pneumonia and CAP than previously reported. Widespread urine antigen testing was not limited by false positivity.

Legionnaires' disease in long-term care facilities: overview and proposed solutions.

Pneumonia is a leading cause of morbidity and mortality in nursing home patients. In acute care hospitals, there is considerable evidence to indicate that Legionnaires' disease is a significant cause of nosocomial pneumonia, the source of which is the potable water system. A relatively limited amount of data exists as to the role of Legionnaires' disease as a cause of pneumonia acquired in long-term care residents. Several lines of evidence suggest that Legionnaires' disease may be an important but underrecognized cause of pneumonia in long-term care residents. These include reports of outbreaks, prospective studies of community-acquired pneumonia that include nursing home patients, and prospective studies of individual long-term care facilities linking Legionnaires' disease to colonization of the potable water system with Legionella. Multiinstitutional studies combining environmental and clinical surveillance for Legionella are needed to further confirm the relationship between colonization of potable water and the occurrence of disease in the long-term care facilities. Until these studies are completed, it is recommended that individual facilities undertake annual sampling of the potable water system for Legionella, coupled with introduction of the rapid Legionella urinary antigen test should L. pneumophila serogroup 1 be found.

Efficacy of new point-of-use water filter for preventing exposure to Legionella and waterborne bacteria.

BACKGROUND: Legionella species cause health care-acquired infections in which immunocompromised patients are disproportionately affected. Epidemiologic studies have demonstrated that point-of-use water fixtures are the reservoirs for these infections. The current approach to prevention is system-wide chemical disinfection of the hospital water system. These methods affect both low-risk and high-risk areas. A more effective approach to prevention may be a targeted approach aimed at protecting high-risk patients. One option is the application of a physical barrier (filter) at the point-of-use water fixture. OBJECTIVES: To evaluate the ability of point-of-use filters to eliminate Legionella and other pathogens from water. METHODS: One hundred twenty-milliliter hot water samples were collected from 7 faucets (4 with filters and 3 without) immediately and after a 1-minute flush. Samples were collected every 2 or 3 days for 1 week. This cycle was repeated for 12 weeks. Samples were cultured for Legionella, total heterotrophic plate count (HPC) bacteria, and Mycobacterium species. RESULTS: Five hundred ninety-four samples were collected over 12 cycles. No Legionella or Mycobacterium were isolated from the faucets with filters between T = 0 and T = 8 days. The mean concentration of L pneumophila and Mycobacterium from the control faucets was 104.5 CFU/mL and 0.44 CFU/mL, respectively. The filters achieved a greater than 99% reduction in HPC bacteria in the immediate and postflush samples. CONCLUSIONS: Point-of-use filters completely eliminated L pneumophila and Mycobacterium from hot water samples. These filter units could prevent exposure of high-risk patients to waterborne pathogens.

Infection due to Legionella species other than L. pneumophila.

In addition to Legionella pneumophila, 19 Legionella species have been documented as human pathogens on the basis of their isolation from clinical material. Like L. pneumophila, other Legionella species are inhabitants of natural and man-made aqueous environments. The major clinical manifestation of infection due to Legionella species is pneumonia, although nonpneumonic legionellosis (Pontiac fever) and extrapulmonary infection may occur. The majority of confirmed infections involving non-pneumophila Legionella species have occurred in immunosuppressed patients. Definitive diagnosis requires culture on selective media. Fluoroquinolones and newer macrolides are effective therapy. A number of nosocomial cases have occurred in association with colonization of hospital water systems; elimination of Legionella species from such systems prevents their transmission to susceptible patients. It is likely that many cases of both community-acquired and nosocomial Legionella infection remain undiagnosed. Application of appropriate culture methodology to the etiologic diagnosis of pneumonia is needed to further define the role of these organisms in disease in humans.

Association between the presence of enterococcal virulence factors gelatinase, hemolysin, and enterococcal surface protein and mortality among patients with bacteremia due to Enterococcus faecalis.

The potential virulence factors of enterococci include production of enterococcal surface protein (Esp), gelatinase, and hemolysin. Gelatinase- and hemolysin-producing strains of Enterococcus faecalis have been shown to be virulent in animal models of enterococcal infections. Esp production has been shown to enhance the persistence of E. faecalis in the urinary bladder. We determined the presence of the esp gene and production of gelatinase and hemolysin in 219 E. faecalis isolates from a larger prospective study of 398 patients with enterococcal bacteremia. Thirty-two percent of isolates carried the esp gene, 64% produced gelatinase, and 11% produced hemolysin. There was no significant association between 14-day mortality and any of the markers studied, singly or in combination.

Staphylococcus aureus rectal carriage and its association with infections in patients in a surgical intensive care unit and a liver transplant unit.

BACKGROUND: The role of rectal carriage of Staphylococcus aureus as a risk factor for nosocomial S. aureus infections in critically ill patients has not been fully discerned. METHODS: Nasal and rectal swabs for S. aureus were obtained on admission and weekly thereafter until discharge or death from 204 consecutive patients admitted to the surgical intensive care unit and liver transplant unit RESULTS: Overall, 49.5% (101 of 204) of the patients never harbored S. aureus, 21.6% (44 of 204) were nasal carriers only, 3.4% (7 of 204) were rectal carriers only, and 25.5% (52 of 204) were both nasal and rectal carriers. Infections due to S. aureus developed in 15.7% (32 of 204) of the patients; these included 3% (3 of 101) of the non-carriers, 18.2% (8 of 44) of the nasal carriers only, 0% (0 of 7) of the rectal carriers only, and 40.4% (21 of 52) of the patients who were both nasal and rectal carriers (P - .001). Patients with both rectal and nasal carriage were significantly more likely to develop S. aureus infection than were those with nasal carriage only (odds ratio, 3.9; 95% confidence interval, 1.18 to 7.85; P= .025). By pulsed-field gel electrophoresis, the infecting rectal and nasal isolates were clonally identical in 82% (14 of 17) of the patients with S. aureus infections. CONCLUSIONS: Rectal carriage represents an underappreciated reservoir for S. aureus in patients in the intensive care unit and liver transplant recipients. Rectal plus nasal carriage may portend a greater risk for S. aureus infections in these patients than currently realized.

Pharmacokinetics of cefoperazone and sulbactam in liver transplant patients.

The authors evaluated the pharmacokinetics of cefoperazone and sulbactam in 9 liver transplant patients. Cefoperazone and sulbactam were administered as an intravenous infusion over 30 minutes every 12 hours for six doses, and multiple blood samples were collected immediately after the first dose (administered during the surgery) and after the last dose. The concentrations of cefoperazone and sulbactam in serum and, when possible, in urine and bile collected over one dosing interval were measured by high-pressure liquid chromatography. The concentration of cefaperazone ranged from 436 to 4118 microg/ml, and sulbactam ranged from 3.3 to 8.7 microg/ml in the bile samples. The intraoperative clearance of cefoperazone (0.53+/-0.18 ml/min/kg) was significantly higher than the postoperative clearance (0.21+/-0.23 ml/min/kg). The half-life of cefaperazone, although not statistically significantly different, was prolonged in all patients during the postoperative period. The clearance of sulbactam (1.51+/-0.51 ml/min/kg) was lower than what is reported in patients with normal renal function but was comparable to what has been reported in patients with renal impairment and in critically ill patients. There were no significant differences in any of the pharmacokinetic parameters of sulbactam during and after surgery. The pharmacokinetic parameters of cefoperazone and sulbactam were significantly altered in liver transplant patients compared to what has been reported in normal subjects but were similar to what has been reported in patients with liver and renal impairment. There was a significant impairment in the biliary excretion of cefoperazone during the postoperative period in liver transplant patients. Although the percentage of the dose of cefoperazone excreted in the bile was drastically reduced, the biliary concentrations were generally high and above the MIC for most organisms. Given that both renal and hepatic elimination of cefoperazone is decreased, leading to a lower clearance and longer half-life in liver transplant patients, lower doses (1-2 g per day) of cefoperazone may be sufficient in liver transplant patients during the immediate postoperative period.

Nursing home-acquired pneumonia: an emergency department treatment algorithm.

Nursing home-acquired pneumonia (NHAP) is a leading cause of morbidity, hospitalization, and mortality among older nursing home residents. Too often, these patients are erroneously grouped with cases of community-acquired and hospital-acquired pneumonia. Yet, they differ in terms of most common pathogens, significant underlying disease, impaired functional and cognitive status, and poor nutrition. The NHAP emergency department treatment algorithm presented here shows that an important decision for initial care in the emergency department (ED) is whether the patient should return to the nursing home. This decision often is based on the facility's ability to administer parenteral antibiotics, and care for co-morbidities and complications. Cephalosporins are the foundation of initial treatment of NHAP in the ED, and are combined with other antibiotics in anticipation of the most likely pathogens and treatment variables discussed here. It is hoped the NHAP treatment algorithm will contribute to improved outcomes.

An economic model: value of antimicrobial-coated sutures to society, hospitals, and third-party payers in preventing abdominal surgical site infections.

BACKGROUND: While the persistence of high surgical site infection (SSI) rates has prompted the advent of more expensive sutures that are coated with antimicrobial agents to prevent SSIs, the economic value of such sutures has yet to be determined. METHODS: Using TreeAge Pro, we developed a decision analytic model to determine the cost-effectiveness of using antimicrobial sutures in abdominal incisions from the hospital, third-party payer, and societal perspectives. Sensitivity analyses systematically varied the risk of developing an SSI (range, 5%-20%), the cost of triclosan-coated sutures (range, $5-$25/inch), and triclosan-coated suture efficacy in preventing infection (range, 5%-50%) to highlight the range of costs associated with using such sutures. RESULTS: Triclosan-coated sutures saved $4,109-$13,975 (hospital perspective), $4,133-$14,297 (third-party payer perspective), and $40,127-$53,244 (societal perspective) per SSI prevented, when a surgery had a 15% SSI risk, depending on their efficacy. If the SSI risk was no more than 5% and the efficacy in preventing SSIs was no more than 10%, triclosan-coated sutures resulted in extra expenditure for hospitals and third-party payers (resulting in extra costs of $1,626 and $1,071 per SSI prevented for hospitals and third-party payers, respectively; SSI risk, 5%; efficacy, 10%). CONCLUSIONS: Our results suggest that switching to triclosan-coated sutures from the uncoated sutures can both prevent SSIs and save substantial costs for hospitals, third-party payers, and society, as long as efficacy in preventing SSIs is at least 10% and SSI risk is at least 10%.

Infections in psychiatric facilities, with an emphasis on outbreaks.

Outbreaks of infectious diseases in psychiatric units are very different from those in intensive care units or acute medical-surgical units. Outbreaks in psychiatric units are most often caused by agents circulating in the community. Infection control in psychiatric units also faces unique challenges due to the characteristics of the patients and facilities.

Risk factors for acquisition of multidrug-resistant Acinetobacter baumannii among cancer patients.

BACKGROUND: Data regarding multidrug-resistant (MDR) Acinetobacter baumannii infections among cancer patients are limited. METHODS: We conducted a case-control study to investigate the risk factors for acquisition of MDR A baumannii and the outcomes among cancer patients. Cases were inpatients with malignancy who had MDR A baumannii from any cultures between 2008 and 2011. Controls were inpatients with malignancy but no MDR A baumannii. RESULTS: A total of 31 case patients were matched with 62 control patients. Hematologic malignancy (P = .036), need for dialysis (P = .01), admission for other reasons except elective surgery (P = .03), transfer from other health care facilities (P = .02), prolonged intensive care unit stay (P = .004), mechanical ventilation (P < .001), pressor use (P = .001), tube feeding (P < .001), transfusion (P = .009), and prior antimicrobial use (P < .001) were identified as significant risk factors in univariate analysis. Need for dialysis (odds ratio [OR], 18.23; P = .04) and prolonged intensive care unit stay (OR, 19.28; P = .01) remained significant in multivariate analysis. Lengths of stay were 28 days for the case patients and 10 days for the control patients (P = .001). The 90-day mortality rates were 41.9% and 29.0%, respectively (P = .20). CONCLUSIONS: Acquisition of MDR A baumannii among cancer patients appears to be associated with general nosocomial infection risk factors rather than underlying malignancies.

Identifying the risk factors for hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) infection among patients colonized with MRSA on admission.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen in hospital-acquired infections. MRSA-colonized inpatients who may benefit from undergoing decolonization have not been identified. OBJECTIVE: To identify risk factors for MRSA infection among patients who are colonized with MRSA at hospital admission. DESIGN: A case-control study. SETTING: A 146-bed Veterans Affairs hospital. PARTICIPANTS: Case patients were those patients admitted from January 2003 to August 2011 who were found to be colonized with MRSA on admission and then developed MRSA infection. Control subjects were those patients admitted during the same period who were found to be colonized with MRSA on admission but who did not develop MRSA infection. METHODS: A retrospective review. RESULTS: A total of 75 case patients and 150 control subjects were identified. A stay in the intensive care unit (ICU) was the significant risk factor in univariate analysis (P<.001). Prior history of MRSA (P=.03), transfer from a nursing home (P=.002), experiencing respiratory failure (P<.001), and receipt of transfusion (P=.001) remained significant variables in multivariate analysis. Prior history of MRSA colonization or infection (P=.02]), difficulty swallowing (P=.04), presence of an open wound (P=.02), and placement of a central line (P=.02) were identified as risk factors for developing MRSA infection for patients in the ICU. Duration of hospitalization, readmission rate, and mortality rate were significantly higher in case patients than in control subjects (P < .001, .001, and <.001, respectively). CONCLUSIONS: MRSA-colonized patients admitted to the ICU or admitted from nursing homes have a high risk of developing MRSA infection. These patients may benefit from undergoing decolonization.